Study of the microstructure, hardness and tribological behavior of hypoeutectic Al-7Si hybrid composites

Abstract

Purpose – This paper aims to investigate the microstructure, hardness and tribological properties of hypoeutectic (Al-7Si) matrix reinforced with fixed quantities of 3 Wt.% graphite (Gr) and x Wt.% SiCp (x = 3, 6 and 9) hybrid composites. Design/methodology/approach – The composites were fabricated by stir cast technique. The microstructure, hardness and tribological measurements were carried out on the base alloy and composites. The tribological investigation was carried out on pin-on-disc wear testing machine under dry sliding condition. Findings – The wear rate decreases with the increase of SiCp into A356-3Gr composites. The composite containing A356-9SiCp-3Gr had better hardness and good wear resistance compared to the base alloy. Scanning electron microscope (SEM) and electro dispersive spectrometry (EDS) images were used to study the reinforcement distribution and worn-out surface of the specimens. Originality/value – The present paper brings out a clear picture of the various events that take place under the worn-out surfaces leading to the generation of mechanical mixed layer.